update GitHub actions + examples (#19)

- update GitHub actions
- update examples
- minor edits

update readme.md (#18)

- update readme.md
  - a.o. rewrite description, future section.
- minor refactor examples
- minor edits

update readme.md (#17)

- update readme.md (badges).
- add performance test example (another).
  - add UNO + ESP32 test results.
- minor edits.

Develop (#16)

* add missing changelog.md

update library.json, license, minor edits (#14)

Arduino ci (#10)

* initial arduino-ci
* add unit tests

Merge pull request #7 from RobTillaart/develop

0.3.1 rewrite readme.md

Merge pull request #3 from RobTillaart/develop

fix #2 added fastMapDouble class

Merge pull request #1 from RobTillaart/develop

fix library.json

0.2.0 version